in index.js [186:212]
  addLambdaInsights() {
    const customLambdaInsights =
      this.service.custom && this.service.custom.lambdaInsights;
    const globalLambdaInsights =
      customLambdaInsights && customLambdaInsights.defaultLambdaInsights ?
        this.checkLambdaInsightsType(
            customLambdaInsights.defaultLambdaInsights,
        ) :
        null;
    const attachPolicy =
      customLambdaInsights && customLambdaInsights.hasOwnProperty('attachPolicy') ?
        this.checkLambdaInsightsType(
            customLambdaInsights.attachPolicy,
        ) :
        true;
    const layerVersion =
      customLambdaInsights && customLambdaInsights.lambdaInsightsVersion ?
        this.checkLambdaInsightsVersion(
            customLambdaInsights.lambdaInsightsVersion,
        ) :
        null;
    return this.addLambdaInsightsToFunctions(globalLambdaInsights, layerVersion, attachPolicy);
  }